Saturday, October 29, 2016

Not exactly the same thing as the current generation of planes! To run on hydrogen, the airlines would require a completely new generation of planes. (source)

Years ago, a Ukrainian colleague told me about a plan that the Soviet Union had for their military presence in the Mediterranean Sea. Because of the long supply lines from the home bases, they were thinking of using their nuclear-powered battle cruisers to produce hydrogen in order to fuel their warplanes.

I have no way to verify whether this story is true or not; I couldn't find any trace of it on the Web. But it is not unreasonable that the idea of hydrogen fueled warplanes was seriously taken into consideration in the 1980s, when the Soviet Union still had dreams of being a superpower. In any case, nothing came out of it and there are good reasons for that: a hydrogen-powered plane is an engineering nightmare for several reasons that are well described in a post by S.H. Salter that Sam Carana published on his blog a few months ago. The full post is reproduced below.

If running a warplane on hydrogen is a nightmare, doing that with the civilian airlines is much worse. Salter makes it clear how complex and difficult the task is. Hydrogen was a good fuel for the Space Shuttle, but the shuttle was not a passenger plane and it carried a gigantic external tank full of liquid hydrogen. This is because hydrogen is a good fuel in terms of weight, but it is bulky. In a passenger plane, the fuel is carried mainly in the wings, but there is just no way to do that with compressed or liquid hydrogen without completely redesigning the whole plane. And that implies replacing the whole fleet of the civilian airlines.

In a little more than a century, we went from the flimsy planes of the Wright brothers to the current generation of wide-body aircraft. The lifetime of the present planes is supposed to be around 30 years or more and it took seven years to deliver the first Airbus A380 (in 2007) from when the decision was taken to design and produce it. And the A380 makes use of proven technologies - it is just one of a long line of aircraft that have been developed and tested over more than 50 years. How long would it take to rebuild the whole airline fleet? Can we afford to do it? Will we have to ground the airlines before it is too late to avoid the worst disasters of climate change?

So, it is easy to write books about the upcoming "hydrogen based economy," assuming that all technical problems can be solved by throwing a little money at them. It is not so easy. Then, of course, there are other renewable fuels that could be used instead of hydrogen, but I will discuss that in another post, but let me tell you that things are not much better. Making a "sustainable plane" is a technological nightmare, at least if we pretend from it the performance we pretend from the current generation of planes.

S H Salter, Engineering and Electronics, University of Edinburgh.EH9 3JL.

The collection of temperature measurements by David Travis following the 3-day grounding of all US civilian flights after 9/11 showed the astonishing effect of jet exhaust on the environment. If burning hydrocarbon fuel in the stratosphere ever becomes a criminal offence, the aviation industry will have an interesting problem. A possible solution is the use of hydrogen as a fuel. Is this technically possible?

The Airbus 380 carries 250 tonnes of fuel with a total calorific value of about 1013 joules. Fuel is stowed in wing tanks but this would be a volume of about one eighth of the fuselage. The calorific value per unit mass of hydrogen is about 3.5 times that of jet fuel and so the weight of hydrogen for the same range would be only about 70 tonnes. Unfortunately the ratio of density of jet fuel to un-pressurized hydrogen is about 9000, so the design problem is how to reduce the volume ratio by about 2500. If we compress hydrogen to reduce its volume by a factor of, say, 100 we still have a fuel volume of 25 times the liquid fuel one or 3.2 times the fuselage volume. The cube root of 3.2 is 1.47 so by increasing all three fuselage dimensions by this factor we could have an aircraft with enough volume for all fuel in the fuselage but no passenger space. An increase by a factor of about 1.6 in both diameter and fuselage length would give enough volume for passengers provided they did not feel unhappy about being close to so much hydrogen.

The immediate reaction against the proposal will be triggered by embedded folk memories of the Hindenburg. Any use of hydrogen will need careful public relations. The Hindenburg survival rate was 64%, much better than crashes of modern conventional aircraft. Deaths were caused by jumping not burning. People who stayed aboard until the wreck reached the ground were unharmed. It is likely that the fire started in the fabric dope rather than the hydrogen. Because spilt hydrogen moves rapidly upwards there is much less risk than from a liquid fuel or heavier-than-air gases like butane or propane which regularly cause devastating explosions in boats and buildings. Furthermore the heat radiated by the invisible hydrogen flame is much lower than that from carbon particles in hydrocarbon flames. We can argue that hydrogen is actually safer than jet fuel, petrol and hydrocarbon gases.

We can spend the 180 tonne fuel weight-saving on gas storage bottles in the form of a low-permeability skin surrounded by wound carbon fibres. A helical winding of aluminium sheet with a low diffusion coefficient for hydrogen looks good. It can be made with the linear equivalent of spot welding. The axial stress in a thin-wall tube under pressure is only half the hoop stress, so we can use the gas tubes as fuselage strength-members. Once the fuselage bending moments are known, we can choose the wrap angle of the windings to give the right balance of directional strength. One structure might be a bundle of nine tubes in a hexagonal array with six full of hydrogen and three containing passengers. A cross section is sketched in the figure. Other configurations are being studied.

The smooth stress paths of the gas bottles would be badly disrupted by the conventional design of landing gear. Can we get rid of it? The requirements for processing the variable energy flows from renewable-energy sources have led to the development of new high-pressure oil machines using digital rather than analogue control of machine displacement. These machines have very high conversion efficiencies and very easy interfaces to computers (see http://www.artemisip.com/ ) . The extremely accurate control of very large energy flows allows many new applications. One of these involves replacing the landing gear of large passenger aircraft with a ground vehicle. Please suspend disbelief until you have considered the following facts:

The landing gear of the A380 weighs 20 tonnes, say, 200 passengers. This weight is carried round the world for many hours and then used for only a few minutes on each flight.

The landing gear occupies a substantial volume of the internal space. The volume restriction limits the travel of the landing gear and so increases acceleration forces.

The requirement for openings compromises the structural integrity of the fuselage and adds weight, even more passengers.

Landing gear must perform with very high reliability despite the weight penalty and extreme temperature cycling.

The full weight of the aircraft must be passed to the ground through highly stressed points.

Gas turbines are very inefficient for moving aircraft on the ground at slow speeds.

On the A380 the shape of the landing gear doors and opening spoils the aerodynamic fairness.

There is a severe design conflict between tyre weight, tyre life and braking performance.

An alternative might be to provide the function of the landing gear by a special-purpose ground vehicle. It would of course have to have VERY reliable links to the aircraft ground approach electronics so as to be in exactly the right place and moving with the right velocity underneath an aircraft on final approach. However there would be no weight, volume or temperature compromises.

The contact between the landing vehicle and the aircraft would be provided by a nest of large air-filled tubes like very large, very soft V-block, running the full length of the fuselage. This would spread the weight evenly into the aircraft skin. The tube surfaces could have vacuum suckers, like an octopus, which could apply shear forces evenly to the aircraft skin. The bags could be on a frame which could have hydraulic actuators to give a much longer travel than the legs of the landing gear. Tilting this frame would remove the need for the angling of the rear underside of the fuselage required to prevent ground contact at V-Rotate. This would further reduce drag during flight. The absence of fuselage penetrations could allow safe water landings for emergency. Runways can have parallel lakes presenting a much lower fire hazard if fuel is spilt. The impact loading on the runway would be much reduced and it might even be possible to revert to grass runways with several parallel operations from any wind direction.

The ground vehicles could use Diesel engines with much higher efficiency at taxi speed than gas turbines. They could have higher acceleration during take off and higher deceleration during landing. The hydraulic transmission would also allow regenerative braking, so the kinetic energy from one landing could be used for the next take-off. All-wheel steering and the option of direct side movement would allow much better use of ground space. The ground vehicle could have many more tyres, which need have no weight or volume compromise to achieve high braking. It could have an air-knife to dry runway surfaces and remove snow. There would be plenty of time to inspect and exchange landing vehicles and they would be in use for a much higher fraction of the time. The landing vehicles could gently lower aircraft on to passive supports at each loading pier and be used for other movements while aircraft were being boarded or serviced.

Images by S H Salter, University of Edinburgh.

The volume of most aircraft wings is much below that of the fuselage and so there is not a strong reason to use gas tubes as structural wing members. However they would offer a way to offset the extra drag of the larger frontal cross-section. From the original work by Prandtl, it has long been known that sucking air from the upper surface of an aerofoil section will reduce the drag by an amount which far offsets the power needed for a suction pump. Schlichting in figure 14.9 of Boundary Layer Theory gives a graph showing a factor of more than two. An objection to suction on wings, where the outer skin is a structural member, is that perforations and slits cause stress concentrations. This should not apply to wing spars made as gas tubes supporting an unstressed skin.

It is important that using fuel does not move the centre of gravity of the aircraft. This happens automatically with fuel stowed in wing tanks. If large quantities of fuel are to be stored in the fuselage it will be necessary to have the centre of pressure of the wings close to the centre of gravity of the fuselage-engine combination. The choice of a ground-based landing vehicle suggests high wings and engine placement above the wing. In theory at least, this will give some advantage from higher air-velocity over the upper wing surface and lower noise transmission to ground level. It is much easier to service and inspect equipment if you do not have to reach above your head. Cranes lifting an engine upwards are much more convenient than forklift trucks working from below. While some change in the architecture of maintenance hangers would be required, high engines accessed from above would by no means be unwelcome to ground crew.

Gas tubes may not be ideal for connections to a low-chord wing and so the longer attachment line of a delta wing, such as used in the Vulcan and Concord and many fighter designs, should be investigated. A flat underside will relax the requirement for precision in yaw during landing. Suction may be able to offset some of the disadvantages of the delta wing as applied to civilian aircraft provided always that they can land safely after a failure of the suction system. A delta wing with a deep thickness and a leading edge made from very strong but transparent material, perhaps poly carbonate, might even allow passengers to sit in the wing enjoying a splendid view if their vertigo allows.

The range of the A 380 is 15,000 kilometres. While this may have been chosen for passenger convenience with the properties of present fuels, it is larger than necessary for trans-Atlantic flights and could allow a further volume reduction. The San Francisco to Sydney distance is only 12000 km and stops in mid Pacific could be very attractive.

Before we waste time on radical new aircraft designs and ground-based landing systems, it is necessary to confirm that burning hydrogen in gas turbines at high altitudes will be a chemically appropriate solution. If we burn hydrogen in ambient air there will be no release of carbon dioxide but there will still be the formation of nitrogen–oxygen compounds collectively known as NOXes. If these are cooled very rapidly, as in the adiabatic expansion of an internal combustion engine, they can be ‘frozen’ at the high-temperature equilibrium state with lots of very nasty acids. The lower combustion pressure and slightly slower cooling of a jet exhaust should be less severe but we want to quantify the severity of the problem. There may even be problems from ice crystals formed from the exhaust. I have asked colleagues at the National Centre for Atmospheric Research at Boulder Colorado for an opinion.

There is one engine design in which the combustion products cool slowly enough for almost all the NOX production to revert to ambient values. This is the Stirling engine originating from 1815 but abandoned because of the absence of materials with good thermal conductivity and high hot strength. Much better materials are now available. By an extraordinary coincidence, the digital hydraulic systems needed for the speed and accuracy of the ground-based landing gear can also radically change the design of Stirling engines by using hydraulics to replace the crank and connecting rods of the conventional Stirling engine. A Stirling-engined aircraft would probably have to use a ducted fan or propeller propulsion but these could still allow civilian aviation to continue in a NOX-sensitive world.

The best way to do experiments on high-altitude engine-chemistry might be from a balloon. Do we know anyone with an interest in this area?

Thursday, October 27, 2016

Theoretically, whatever is published in a scientific journal should go through a rigorous review process that ensures that it is correct and reliable. Unfortunately, it doesn't work that way.

If you follow the debate on renewable energy, you know how important is the question of the energy return (or EROEI) of the various sources. An EROEI lower than one would make the source - PV, wind, or whatever, an energy sink, not a source. And this is exactly what Ferruccio Ferroni and Richard Hopkirk have been claimed with a paper recently published in "Energy Policy" that arrives to results that are completely different than to those of all the other studies on the subject.

The paper by Ferroni and Hopkirk is simply wrong. You can read below a complete demolition of their arguments performed by Maury Markowitz. But, no matter how wrong is the paper - and it is wrong - this story raises some disturbing points about how scientific information is validated and diffused.

1. Any paper, no matter how bad, poorly conceived, and ultimately totally wrong, can be published in a scientific journal if the authors are persistent enough and try many times. Eventually, they will find a combination of editors and reviewers sufficiently incompetent, sloppy, or biased that they will accept it.

2. There is no way to correct the mistakes of a wrong paper once it is published. The journal will retract it only if it is possible to prove that the authors are guilty of evident fraud or plagiarism. But "simple" mistakes, things such as wrong citations, misinterpreted data, inappropriate data treatment and the like are rarely sufficient to force retraction.

3. The only way to protest against a wrong paper is to ask to the journal to publish a rebuttal. They will do that with the same degree of willingness that you feel about having a tooth pulled, but they will do that, asking also to the authors of the original paper to write a counter-rebuttal. The whole task is long, painful, and ultimately useless as it may end up giving more visibility to the initial paper.

4. Mark Twain is reported to have said that "A Lie Can Travel Halfway Around the World While the Truth Is Putting On Its Shoes". That's exactly what happens when a wrong paper sees the light in a scientific journal. It will spread fast with the people who are seeking for whatever can help them with their confirmation bias. And the rebuttals will be considered as proof of the conspiracy by the PTBs to suppress the Truth.

That's exactly what's happening with the F&H paper, gleefully paraded around as proof that photovoltaic energy is a scam and a waste of money. A rebuttal to the paper is in preparation by a group of scientists, but it will arrive late and will do little to correct the wrong information already diffused on the Web. The problem is that this information affects choices that will determine our future: we can't afford to base them on wrong studies that somehow managed to get published.

So, how did we find ourselves into this mess? Who created a scientific review system that has no quality standards, no independent quality control, no audits, no nothing? I have no idea, but it is clear that the system badly needs a serious reform.

Here is the demolition of the Ferroni and Hopkirk paper, reproduced from Markowits's blog

Another PV ERoEI debacle May 17, 2016

Your face should have this expression when you read Ferroni and Hopkirk’s paper.

A recent report by Ferroni and Hopkirk explores the energy balance of solar power, and concludes that using PV is energy negative. That is, building PV requires more energy than the panel will produce over its lifetime.Claims like these pop up from time to time, and normally end up being based on definitional tricks on the part of the authors. This example is no different in that respect, but in this case they also add a liberal dose of bad data.The paper is so filled with errors and omissions that’s it’s almost breathtaking. Once again, dear reader, it’s time for the deep dive.

The sincerest flattery

While googling myself (I can’t remember my URL any more than you can) I found to my delight that the name of this blog has been taken up by a pair of bloggers from Aberdeen. How I never came across this previously is something of a mystery; I guess the web is deeper than one would imagine.In any event, a May 9 post by one of the authors pointed me to the paper that is the topic of the rest of this article. After stating that the topic of ERoEI is new to the blog, he goes on to note that when he came across this paper, “the findings are so stunning that I felt compelled to write this post immediately.”When I come across a study in the renewables field with findings that are “stunning”, I normally hold it at arm’s length until I can run the numbers myself. That’s because the field is utterly filled with bogus information from thinly disguised coal company shills to the nuclear true believers.

Don’t get me wrong, there’s just as much BS going the other way, from the usual suspects to the space heads, which is all the more reason to be super-skeptical. While Mr. Mearns does make some comments about the validity of certain inputs in theoretical terms, in the end, he quotes the bottom line:

Solar panels will produce only 0.83 times the amount of
energy they take to produce… If correct, that means more energy is used
to make the PV panels than will ever be recovered from them during their
25 year lifetime.

That’s a big “if correct.”And guess what, it’s not correct.

Start bad…

So let’s get into the meat of it. The paper starts with the authors having examined 28 other papers on the topic and found they had a wide variability of Cumulative Energy Demand (CED), the amount of energy used by a product over its lifetime. They conclude that “the authors … were not following the same criteria in determining the boundaries of the PV system.”

Now getting the CED is important, because the overall energy balance, ERoEI,i s basically energy out divided by energy in. So you’re going to need to have a good value for that CED, and there’re all over the map. So their solution is to define an entirely new version – yay!But now they change gears, and work on the other side of the equation, the total energy produced.

And they attempt to do this in per-square-meter terms.Now stop right there.The industry, and I mean the entire power industry here, not just the renewables industry, measures everything in either per-watt or per-kilowatt-hour terms. That’s because the physical mechanisms of the generators differ wildly, but a watt is a watt, so when you convert to those terms you have a real apples-to-apples comparison.Consider an example; if I tell you a hydro dam cost $2/Watt and a new wind turbine costs $1.50/W,well, there you have it. Now what if I told you that the dam cost $2 per square meter and the turbine $10? Well, does that area include the reservoir? Does the turbine include all the area around it, or just the actual footprint on the ground? See the problem? Area is tough to pin down. Dollars are not.

So why would the authors pick such an odd unit? I can’t say for sure, but in the abstract they mention something about how “solar radiation exhibits a rather low power density”. Well, sure, and that’s important why? Apparently it’s not, because it only figures in very peripherally in the calculations, and has no effect on the bottom line.Whatever, let’s get to the numbers at hand:

The data are available in the Swiss annual energy
statistics … and show an average value of 400 kW ht/m2 yr (suffix “t”
means “thermal”) for the last 10 years. This is an indication of the
rather low effective level of the insolation in Switzerland. … The
uptake from the incoming solar radiation is converted into electrical
energy by the photovoltaic effect. The conversion process is subject to
the Shockley-Queisser Limit, which indicates for the silicon technology a
maximum theoretical energy conversion ef- ficiency of 31%. Since the
maximum measured efficiency under standard test conditions (vertical
irradiation and temperature below 25 °C) is lower, at approximately 20%,
the yearly energy return derived by this first method in the form of
electricity gen- erated, amounts to only 80 kW he/m2 yr.

Ok, if you don’t really know much about solar power, you might not immediately see the problem with this statement. What they’re doing is a double conversion – they’re not calculating the amount of energy produced by a PV panel, they’re taking the amount of heat collected by a thermal panel, then applying a formula to convert that to expected electrical power production.

But that conversion is totally wrong. The Shockley-Queisser Limit doesn’t work on thermal energy, it works on the original solar energy. And no, the thermal energy is not a good proxy for the original solar energy. The main contribution to the losses in PV, the SQ limit, is wavelength, which doesn’t come into play in thermal collectors at all. And the main contributor to losses in thermal collectors is ambient temperature, which has a minor effect on PV.The two are just not the same, you can’t do that.But more to the point, why would they do that? Because the same source they quote for the thermal value publishes actual electrical output figures as well, which they then go on to quote:

According to the official Swiss energy statistics (Swiss
Federal Office of Energy, 2015), an average for the last 10 years of 106
kWhe/m2 yr is obtained for relatively new modules.

This number is 30% higher than their calculation based on thermal, a discrepancy they don’t even try to explain.Beyond that, any number that is “an average for the last 10 years” is, by definition, not talking about “relatively new modules”. Ten years ago the average panel was about 160 Watts and cost about $5.00/Wp. Today they’re around 280 Watts and cost about $0.45/Wp. The vast majority of the world’s PV was installed in the last three years, so any calculation based on data older than that is just plain wrong.

And even this number, 106, is significantly lower than

I would expect given that Switzerland has fairly average insolation for mid-latitude Europe. So what’s up with that?Well when I checked the cited source I found that no such number is actually reported. One can only find total output numbers and then work back from there, but the authors fail to give their calculation. And those totals -wait for it- go back over a decade, so we’re right back to that problem again.Which is all the more funny when you consider that such data is trivially available on the ‘net. Anyone who wants do to do this calculation should do what we all do; use NREL’s PVWatts. It has highly accurate weather data going back 30 years taken only from first-class sensors.I typed in Zurich for the location, and selected the TMY3 data set. For the system size, I considered a typical modern 280 Watt panel at 1.6 m², or 175 W/m², and typed 0.175 into the System Size. I also changed the tilt from 20, which is good for California, to 30, which is good for Zurich. And here it is:

They said 106. We’re at the very first number in the paper, and they’re already off by a factor of 60% from what the industry standard tool suggests.No attempt is made to explain this, except for dismissive comments about industry calculators.

…get worse…

Now the authors turn their attention to expected lifetime of the panels, which is needed in order to calculate the overall lifetime energy production. They do so in a rather convoluted fashion, starting by considering the amount of panels recycled in Germany:

Hmmm. A SolarWorld 280, a typical modern panel, masses 17.9 kg. That’s 17.9/1.6 = 11.2 kg/m². I really have no idea where they got their value, and they don’t include any sort of reference. A 1 MWp system using these panels would require 1 million / 280 ~= 3570 panels, or 3570 x 17.9 = 63,903 kg = 64 t. So now we’re at calculation number two, and we find they’re off by another factor of two.The paper goes on to use these numbers to suggest a real lifetime is about 17 years. Now the problem is that if older panels are heavier, then the number on a per-kg basis is automatically skewed towards older panels again. Or to put it another way, if you had 10 panels from each year since 1990 and scrapped one from each year, when measured by weight it would seem that more older panels are dying.And once again I’m left scratching my head why they would use this convoluted magic, when one can find real values in seconds. In fact, one of the most quoted examples is right up the road from them on the LEEE-TISO buildings. The vast majority of these panels, apparently the first grid-tie system in the world, are still running fine after almost 35 years now. They calculate the losses at 0.2 to 0.5% a year, which corresponds to a panel lifetime on the order of 60 years.

…a little more…

They then ignore their previous calculations, and use a 25 year lifetime. So apparently all of that was for nothing! And that brings us to this:

Experience has shown that, on average, efficiency and
hence performance de- gradations of around 1% per year of operation must
be expected (Jordan and Kurtz, 2012).

Now we go from bad to terrible. They claim this 1% number comes from a paper by Jordan and Kurtz. Well that paper is available online, and actually states the measured rate varies widely, from 0.23% to as much as 2%. And the mode among that data is between 0.4 and 0.5%, which you can see on page 4 of the paper.So if the paper they quote says it is 0.5%, how do they get 1% from the same report? Because they chose the figure on the right of page 4, which includes low-quality data. And what is the difference between the two? Well, the low-quality data is:

very sensitive to several sources of error that could
skew the results. Soiling, maintaining calibration and cleanliness of
irradiance sensors, module baseline data (nameplate vs. flash test), and
not appropriately accounting for LID are just a few major sources of
data errors.

In other words, the high-quality data is based on controlled measurements, where they account for these effects and report only the actual panel degradation. In contrast, the low-quality data does not account for these issues, so it includes all sorts of external environmental effects. They fail to mention any of this, they knowingly use the bad data.

They also fail to mention that while the 1% value was indeed used by the industry in the past, they number the industry now uses is 0.5%. And that’s because a number of long-period studies demonstrated 1% was too high. In particular, a NREL study found that panels made before 2000 had a degradation rate of 0.5%, and those after 2000 fell to 0.4%. That indicates the sorts of improvement processes that continue to this day. And, of course, they have the LEEE-TISO numbers, which strongly agree with both of the sources quoted above.Ferroni and Hopkirk then claim:

There are also other, external factors, which can reduce
PV module lifetime, for instance the site, the weather and indeed
climatic conditions. These aspects do not appear to have been treated in
the scientific literature in connection with photovoltaic energy usage.

Oh come on! They actually talk about these factors in the paper they’re quoting! These sorts of effects are also considered in every tool that predicts output, including PVWatts. And what, do they think their weather would be any different than the LEEE-TISO install down the road from them? Ugh.

…which brings us to…

Ok so now all of this feeds into this equation:What this does is add up all the yearly power production figures over the lifetime of the panel to produce the total energy output of the panel. And using their figures they get 2203 kWhe/m².

Ok, just for funzies, let’s run the exact same equation,but we’ll use NREL’s 30-year climatic data, and the industry-standard 0.5% degradation. That gets you 3795 kWhe/m². Almost double.And I need to point out that I’m using industry standard numbers, and in one case, from the same paper they quote. Their result is lower simply because they have selected worst-case-scenarios for all of these numbers. Normally one would indicate this with error bars or using the mode or mean values, like I’m doing here, but they haven’t done that. They just say these numbers are correct. They aren’t.

So, now, the other side of the equation

Ok, so the authors have now developed a number for the total output of the panel, now it’s time to consider the total energy input. And that starts like this:

The average weight of a photovoltaic module is 16 kg/m2

As I noted earlier, the SolarWorld example I linked to above is 17.9 kg for 1.6 m², or 11 kg/m². I assure you this is typical, but feel free to Google “solar panel weight” if you don’t believe me. And then they go on to state:

and the weight of the support system, inverter and the balance of the system is at least 25 kg/m2

25 kg for every square meter? I’ve installed a number of crazy systems, and I can assure you, we never came even close to that. Invariably the heaviest part was the panel.

So let’s check on their sources. Well, first of all they don’t actually quote the original source for those numbers, they quote a University of Toronto thesis from 2009 where you’ll find that:

Support structures for PV panels are made from aluminum or steel, with the majority of systems using steel.

The majority use steel? Uhh, no. And the 25 kg/m² figure in there? It comes from two even earlier papers from 2007. And when I looked there, the one that did have the 25 figure was quoting that from the other, which didn’t have that number in it. I really have no idea where it comes from.

There’s only so much time we can spend on that madness. So let’s just use the power of the internet to find modern values. Check out page 6 of this fairly modern product guide to mountings, which puts the total weight of mounts and panels at 16 kg/m². If we use the modern figure of 11 kg/m² for the panel, that puts the weight of the support structure at 5 kg/m². That same guide also includes values up to 50 kg/m², but that’s for ballast on flat roofs, which are concrete blocks, not steel. This is not used on sloped roofs or ground mounts, but as it might represent as much as 15% of the market, you can factor that in as you wish.

Since the total lifetime energy return is 2203 kW he/m2, we obtain a material flow of 20.2 g per kWhe

Maybe. Or maybe it’s 19,500 / 3795 = 5.1 g/kWh? Once again, using numbers from the industry I get a number four times “better” than they do.

Now why is this important? Because that number is basically how you calculate the energy needed to make the panel and rest of the system. So much weight of steel takes so much energy to make, and so forth. So if you reduce that by four, you’re almost reducing the CED by four, right off the bat.

Show me da money!

So now the authors move onto the “use of capital.” The basic idea here is that money embodies energy, in a way. Basically everything requires energy to build and ship to you, so if you spend $1 on something, some of that is paying for that energy. So, on average, you can say that a dollar of capital has a certain average energy content, which for convenience, we’ll express in kWh.

So if we’re going to start down that road, we need to have some sort of value for how much capital we need. Here’s the relevant part:

The actual capital cost for a sample group of fully
installed PV units, 2/3 roof-mounted and 1/3 free-field-mounted, in
Switzerland lies at or above 1000 CHF/m2 with large cost variations of
up to 30%, due principally to the uncertainty in the price develop-
ments of PV modules. The NREL (National Renewable Energy Laboratory of
the U.S. DOE) reports capital cost for fully installed PV units in the
lower end of the price range given above. The 1000 CHF/m2 cost,
translated into specific cost for installed peak power is 6000 CHF/kWp
and is a result of personal experience of the authors.

Ok ok, let’s take this bit by bit. First they have a 2/3 roof and 1/3 field split. They don’t provide a source,of course. I’ve never seen numbers anything like this, and it is trivially easy to find industry values that show the opposite.

For instance, even in Germany where the majority of installs were residential, they represent only 35% of the total buildout. In the US, where the split used to be about 50/50, utility installations now far outnumber residential. Now I mention this because utility installs are ground-mount, so according to these recent sources, the total installed base should be at least the opposite of what they use in this paper.

And this is important, because the capital cost of the system is roughly double for roof mounts, especially residential. That’s because you’re installing far less panels per job, so setup and administration is a lot more on a percentage basis. And for that reason, utility scale installs are dwarfing residential these days, a move that continues to accelerate every year.

Which brings us to the second number, the actual capex value they will use from here on in. That number is 1000 CHF/m2, but that translates into 6000 CHF/kWp based on the “personal experience of the authors”?!

Really. In a peer reviewed paper, we’re being told just to take their word for it. Wow.

Well they can’t be bothered to cite their numbers, but I’ll cite mine. I will refer to the most comprehensive and up-to-date industry-measured values one can easily get, the yearly Lazard LCoE report. And that number, averaged across the western world, is found on page 11, and it is $1500/kWp for utility and $3500/kWp for residential.

Using the modern 1/3rd residential, 2/3rds commercial split, that gives us (3.5*.33)+(1.5*.66) = $2145/kWp average. Now to make a kWp of panel using those SolarWorlds, we need 1000 / 280 = 3.57 panels, and since each panel is 1.6 m², we need 3.57 x 1.6 = 5.7 m², so on a per-m² basis that’s $2145 / 5.7m² = $376 / m².

That’s less than 1/3rd the number they’re quoting, although they do so out of thin air. Even this number overestimates the contribution of residential installs moving forward. I prefer to use the utility rate as more indicative of the real capex of PV; $1500 / 5.7m² = $263 / m².

Working in a coal mine

The paper then moves onto breaking out the various components of that cost and calculating the energy value of each one. They start with labour. After quoting four year old figures, they say:

Based upon the authors’ experiences for typical local
labour costs per square meter of PV module are: project management (10%
of capital cost), installation (506 CHF per m2), operation for 25 years,
including insurance (1.67% of capital cost per year for 25 years) and
decommissioning (30% of installation). The total labour costs amount to
1175 CHF/m2.

Now in case it’s not obvious, I want to point out that all of these measurements are based on the capital cost. So if your capital cost is off, this is too. And their capex is off by a factor of three to four. Because, once again, it’s just “the authors’ experiences”.

And to make my point, consider that value in the middle, the installation costs. They’ve already said that the total capex for the system is 1100 CHF / m², and here they say that installation labour is over 500 of that, roughly half.

Really? According to these numbers, published only months ago, all soft costs put together cost around 52% of the system price. And you’ll note that number puts all-in prices at 1300 Euro, basically identical to the Lazard number at $1500 US, and, once again, 1/4 the number Ferroni and Hopkirk create out of thin air.

So for the moment, lets ignore their made-up numbers and use these industry standard ones. They calculate 505 kWhe/m² based on 1175 CHF/m² of labour. Using these figures we see that all the soft costs are 52% of 1300 Euro per kWp, or 748 CHF/kWp, or 209 kWhe/m².

But what’s another factor of two between frenemies?

And finally, in section 5.5.3, the duo calculate the energy value of the capital itself. Basically the idea here is that if you have to borrow the money (or you can flip that to opportunity cost, same thing) then you could express that in terms of panels you could have bought with that interest (so to speak). You can think of that as “lost energy” in a way…

Using their rate of 1100 CHF/m², they get a value of 420.

Using the industry rate above, 1300 Euro/kWp, that gets us around 120.

Show me da money (again)!

Which brings us, finally, to their totals in Table 4:Now let’s do the exact same thing using the numbers we’ve calculated:

CED

1300

Integration

349

Labour

209

Faulty equipment

90

Capital

120

Total

2068

So basically, just considering the known-good, widely-available capex number, we’ve reduced the “energy investment” by 22%.

All of this goes back to the original claim. They claim that the ERoEI is 2203/2664 = 83%. But a whole lot of that is made up by the cost of capital, based on a bogus number. By changing that one number to the one actually measured in the field, we get 2203/2068 = ERoEI 1.06.

And if we instead insert NREL’s number for the insolation, and use the industry standard degradation, it becomes 3795/2203 = ERoEI 1.7. That’s better than fracked oil in the US.

And we haven’t even touched that CED number, which, as you can see above, is based on some rather odd numbers about system weights.

That’s not all folks…

Now we come to the issue of recycling. In the calculations in the paper, the authors consider the panels to have a 30% decommissioning fee, which is added in the labour term.

But they totally ignore the salvage value of the panels. Panels are basically glass, aluminum, some silver and some copper. People pay for these things, which is precisely why the Europeans have a recycling program for panels.

Given an average 50% energy recovery for recycling, we can reduce the CED of a 2nd generation panel to 650. Running the same calculation gets us 1419, so 2203/1419 = 1.55, or 3795/1419 = 2.7.

And if you do consider the recycling as a potential revenue stream, then the labour line is reduced by some portion of that 30%, which brings the denominator to 1340. And that gives 2203/1340 = 1.64 or 3795/1340 = 2.83.

So in the end

Consider this: the calculation they use in their paper would produce different results if the interest rate changes, the FX rate between the Yuan and Swiss Franc changes, or the price of installations continues its astonishing downward fall.

So, what exactly is this figure measuring?

It’s certainly not measuring anything like the “embedded energy content” of the panels. That wouldn’t change just because someone types a number into a Bloomberg terminal. Yet that’s precisely what happens using their calculation.And finally, I need to point out the glaring fact that the authors don’t run the same calculation on any other power source. Given that sources like nuclear are far more capital intensive than PV (which is why no one is building them) their calculation of “ERoEI” is worse.

This paper is just plain bogus. The entire methodology is based on numbers that have no physical reality (money) and the authors deliberately cherry pick data to make those numbers “prove” their point, or just make up values out of the air. All of this is glaringly obvious, and is simply yet another example of the sorts of attacks renewables face at the hands of the true believers in the nuclear field.

Saturday, October 22, 2016

"Energy too cheap to meter" was the mother of all promises (above, Disney's atomic genius from 1956). Unfortunately, science failed utterly to deliver this and many other promises made during the "nuclear age," and even later. Eventually, people will realize how much hot air there is in the press releases about pretended scientific breakthroughs and, already today, we shouldn't be surprised if so many people don't trust what the scientists are telling them about climate change.

In the 1950s, during the high times of the "atomic age", someone had the unfortunate idea of claiming that nuclear technologies would give us, one day, "energy too cheap to meter." We might call it "the mother of all promises" and, of course, it was not maintained. But, as propaganda often does, it stuck in people's minds and it seems that many people still believe in the concept that energy too cheap to meter is just around the corner. Many seem to expect it to come with one of the many scams about "free energy" or "cold fusion" that litter the Internet today.

But breakthroughs bordering on miracles are claimed also in other fields of science and some scientists seem to have made a point in saving the world every two weeks or so. The latest scientific claim that went viral on the web is about a catalyst able to turn CO2 directly into ethanol. It is likely that many people understood as a miracle that would remove the dreaded CO2 from the air and transform it into something useful at little or no cost.

Yet, if you look at the original article, you will find nothing that suggests that this catalyst is ready for practical, real-world applications. There are no data about how long it can last in operating conditions, nor there are calculations that would tell us how efficient would be the whole process, considering that one has to saturate the electrolyte with CO2. The authors themselves state that "The overpotential (which might be lowered with the proper electrolyte, and by separating the hydrogen production to another catalyst) probably precludes economic viability for this catalyst." So, we have something that works in the lab, which is fine, of course, but we should never forget that the graveyard of failed inventions is littered with tombstones with the inscription "in the lab, it worked."

In the discussion that took place on Facebook about this story, some people asked me why I was criticizing this paper so much; after all, they said, it is a legitimate research report. It is true, but the problem is another one. What is the public supposed to think about this?

Most people will see only the press release and they lack the intellectual tools needed to understand and evaluate the original. And from the press release hey will understand that scientists are making a new claim of a further scientific miracle that will solve some important problem at some unspecified moment in the future. And then the whole story will be forgotten and the problems of climate, pollution, depletion, etc., will still be there; worse than before.

It is true that the myth of the scientific miracle is stubborn, mainly because it is a comfortable myth: nobody has to do anything except giving some money to our priests in white coats. But that can't last forever. Science, as all human enterprises, doesn't live in a vacuum, it lives on its reputation. People believe that science can do something good for them because science has done that in the past. But this reputation is being tarnished a little every time some hyped scientific claim falls into oblivion, as it is destined to do. The reserve of trust that science has accumulated in the past is not infinite.

Already today, you can see the decline of the reputation of science with the many people who believe that no man ever never walked on the moon. Even worse, you can see it with those (nearly 50% of the American public) who believe that human-caused climate change is an elaborate hoax created by a cabal of evil scientists who are only interested in their fat research grants.

So, what happens when the reserve of trust in science runs out for good? I don't know, but wouldn't it be a good thing for scientists to be a little more humble and stop promising things they know they can't maintain?

Sunday, October 16, 2016

The results of a Google Trend search for "Friendster", an old social network. It is a nearly perfect "Seneca Shape," where decline is faster than growth.

"Friendster" was a social network that, in many ways, pre-dated Facebook. Friendster collapsed rapidly, starting in around 2009, providing us with an impressive example of a "Seneca Shape", a curve where decline is much faster than growth, or, as Seneca the philosopher said long ago, "ruin is rapid".

Basically, there must be more than one way to skin a platypus: both the studies cited are based on collective feedback effects, which is the crucial factor that makes collapses occur. So, network theory is more detailed, system dynamics is more aggregated, but we are describing the same phenomenon, although from different viewpoints.

In both cases, anyway, we find that ruin is rapid. As long as it occurs to an obsolete social service, it is not a big problem. But if it were to occur to something massive and vital for civilization, such as the oil industry, then we could see something like this.... ouch.......

Friday, October 14, 2016

Just a little note about something I noticed a few days ago in a hotel room. Note the ubiquitous sign where they ask you whether you want to be environmentally friendly by not having your towel replaced. I don't think there remains a single hotel in the whole world where they don't ask you that.

But, in this case, the sign is placed right near the tower rail heating system; it is electric, not part of the room heating system. And there is no obvious way to turn it off in case you feel that your towels are warm enough at the temperature of the room.

Maybe you could make an LCA study that will tell you that an electric rail-heating system is less energy hungry than having a towel washed. Or maybe not. But it is funny that how successful a plea for being environmentally friendly can be. And how meaningless, considering the amount of energy that the people staying in hotels must have used to get there.

So, in the end, asking you if you want your towel washed or not seems more than all a little propitiatory spell to make you feel good. Maybe you flew there all the way from the other side of the world, spwing untold amounts of CO2 into the atmosphere. But, what the hell, you are a friend of the environment and you will keep your wet towels on that electrically heated rail!

Wednesday, October 12, 2016

Today, in Cambridge, a meeting was held with several of the authors of the "Glimpses" that were part of the "2052" book by Jorgen Randers. The idea was to update the forecasts that were published in 2012.

Randers showed the update of his model, obtained with new data and with some modifications of the model itself. In five years, there have been modest changes and the basic results of the initial model are confirmed. Basically:

1. Randers' model sees the growth of both the economy (in terms of GDP) and of the population up to 2052; although the forecasted population is less than 9 billion people, much lower than the UN predictions.

2. Randers' model doesn't see scarcity for any resource, at least up to 2052

3. Inequality and poverty will remain as significant problems.

4. The model clearly says that we are NOT staying below the 2 degrees limits. Renewables will be growing fast, but so will do fossil fuels at least for another couple of decades. Randers' climate model (a different one) doesn't produce a "climate tipping point" for the rest of the century, but the raising temperatures will do enormous damage to the world's economy and to people.

Of course, forecasts are always difficult, especially when dealing with the future. My modest opinion is that Randers' model is good and I was impressed by the work that was done and that's being done to keep it up to date and to improve it; so I think that these results should be carefully studied and understood.

Then, still according to my modest opinion, there remains a fundamental problem: models based on system dynamics are not really made to catch tipping points. I think Randers is right when he says that we won't see the climate "catching fire" during this century. We may well be on our way to an ice free planet (and the corresponding 70 m of sea level rise) but that will not be for this century (hopefully!). The kind of tipping points that we are more likely to see are the result of coupling between the climate system and the socio-economic system. For instance, no model could predict the Syrian disaster, and yet its root cause is the double whammy of global warming and oil depletion. What can happen in the future as temperatures keep rising and resources being depleted, it is probably impossible to predict by any model.

But the meeting of today produced also elements of hope. The idea that renewables can make it seem to be diffusing and I myself presented the results of the study that we performed with Sgouridis and Csala that demonstrates just that. Others argued that the financial system is gearing up to provide the necessary resources for the transition. And, who knows? We might really make it! The future cannot be predicted, but we can always hope for a good future!

Saturday, October 8, 2016

Kite surfing on the Ĳsselmeer lake, in the Netherlands; a picture that I took a couple of weeks ago. These are not kites for airborne wind energy (AWE) but, for some reason, Holland is the country where the idea of energy kites seems to be most popular; in particular because of the work of the late Wubbo Ockels (1946 – 2014), pioneer of wind energy. The technology is promising, but there is a long way to go before it will become a commercial reality.

I have been following the development of airborne wind energy (AWE) for more than 10 years and I keep following it. This summer, I visited the campus of the Technical University of Delft, in Holland, where I met the people of "Enevate", the university spinoff dedicated to kite power, a field in which the university of Delft has been active for a long time. I found a dedicated group of young people, enthusiastic and competent, working hard at developing the concept. Recently, they scored a remarkable success obtaining the support of the EU Horizon program for the project "REACH" dedicated to airborne wind energy.

But where do we stand, today, with this technology? The idea of AWE is both simple and promising. The current generation of wind turbines work relatively well, but it is also a technology that's rapidly reaching its technical limits, given by the weight and the cost of the tower that supports the rotor. So, why can't we just get rid of the tower and have the rotor fly in the air? Think how much money we could save!

So, we fly a kite. The kite catches the wind energy and transmits it down to earth either by onboard generators or by pulling cables that act on a ground-based generator. This technology is called in various ways, but the term "Airborne Wind Energy" seems to have become the most common one. The development of this field has been going on for at least ten years. Some years ago, I wrote an early (rather overoptimistic) paper on the concept on "The Oil Drum." Recently, Euan Mearns wrote an also rather optimistic, but reasonably well-balanced, post on the subject. A much more negative review of AWE appeared in "GreenTech" as well as in another article published by some researchers of the Max Planck institute. You can find a recent review of the various technical implementations of the idea in a paper written by Cherubini et al.

So, where do we stand, today? There is no doubt that the concept of AWE is alive and well and that research on it is being performed in several laboratories all over the world with the support of governments and companies. The problem with all promising technologies is always the same: the promise must be kept. The technology must work and we can say that it does only if we have something that works and can be tested for a relatively long time. We don't seem to have arrived at that stage yet with AWE, but it is normal: research and development is a slow and expensive process; not something for mad scientists building spaceships in their basement. In my opinion, some early dreams of tapping the wind at very high altitudes, even getting energy from the jet stream, were much too ambitious. But that doesn't mean that the technology can't work. What can be done at the present stage is to work on small systems that go no higher than about 1000 m and that are manageable and relatively simple. Even for these systems, it takes time; there are still plenty of problems to solve. As somebody said, research is "1% inspiration and 99% perspiration". With AWE, there is still a lot of perspiration to do.

One problem when dealing with energy producing technologies is the "miracle trap." We all know that we have an enormous problem with fossil fuels in terms of both depletion and pollution. We need to replace them with renewable energy as fast as possible and most of us understand that it won't be easy (although not impossible). So, some people are actively searching for miracles and some found them in outright scams about cold fusion or mysterious unknown nuclear processes. Others use their faith on the miracles that will come as an excuse for doing nothing. And, finally, others have fallen into the opposite trap and tend to consider as a scam anything and everything that hasn't yet fulfilled its initial promises. Some people seem to have developed this attitude even toward AWE. But AWE is neither a scam nor a miracle. It is a technology being developed that needs to be studied and evaluated.

AWE may well fulfill an important role in energy production in the future but, for the time being, we need to deploy what works, and keep working on what's promising. And if we keep a cool head, we can make it even with what we have. We don't need miracles; we need to work for our future. And we need to start right now.

Wednesday, October 5, 2016

An excerpt from the book I am writing, "The Seneca Effect," that contains a chapter dedicated to the Irish famines. Above, the reverend Thomas Malthus (1766 - 1834)

The demolition of Thomas Malthus' work in our times is often based on accusing him of having predicted some awful catastrophe to occur in the near future, sometimes on a specific date. Then, since the catastrophe didn't occur, there follows that Malthus was completely wrong and nothing in his work can be salvaged. It is a well-tested method that was used with great success against "The Limits to Growth", the report to the Club of Rome that appeared in 1972.

Except that Malthus never made the "wrong predictions" attributed to him, just as "The Limits to Growth" never made wrong predictions, either. There are no specific dates in Malthus' book "An essay on the Principle of Population" for where and when famines or other catastrophes should take place. For instance, Malthus says that,

Famine seems to be the last, the most dreadful resource of nature. The power of population is so superior to the power in the Earth to produce subsistence for man, that premature death must in some shape or other visit the human race. The vices of mankind are active and able ministers of depopulation. They are the precursors in the great army of destruction; and often finish the dreadful work themselves. But should they fail in this war of extermination, sickly seasons, epidemics, pestilence, and plague, advance in terrific array, and sweep off their thousands and ten thousands. Should success be still incomplete, gigantic inevitable famine stalks in the rear, and with one mighty blow levels the population with the food of the world.

Doomerish, you can surely say, but not something that you can define as a "wrong prediction". Events similar to Malthus' description really occurred before Malthus times and in the “Essay” he normally refers to historical cases, especially those that had occurred in China.

So, Malthus was not babbling about dark and dire things to come; he was describing and analyzing events that were well known in his times. But few people, today, seem to be interested in looking up the original text and prefer to maintain that “Malthus was wrong” by repeating the legend. And, by the way, even if Malthus had been guilty of “wrong predictions”, that doesn't mean that infinite population growth could take place on a finite planet.

The other way to demolish Malthus's ideas is to paint him as evil, in the sense that he had proposed, or favored, mass extermination as a consequence of his ideas. This is, also, a common legend and also a great injustice done to Malthus. Over the great corpus written by Malthus, it is perfectly possible to find parts that we find objectionable today, especially in his description of “primitive” people whom he calls “wretched”. In this respect, Malthus was a man of his times and that was the prevalent opinion of Europeans in regard to non-Europeans (and maybe, in some cases, still is, as described in the book “Can Non-Europeans Think?” (Dabashi and Mignolo 2015).

Apart from that, Malthus’ writings are clearly the work of a compassionate man who saw a future that he didn't like but that he felt was his duty to describe. Surely, there is no justification in criticizing him for things that he never said, as it can be done by cutting and pasting fragments of his work and interpreting them out of context. For instance, Joel Mokyr in his otherwise excellent book titled “Why Ireland Starved”⁠ (Mokyr 1983) reports this sentence from a letter that Malthus wrote to his friend David Ricardo,

The land in Ireland is infinitely more peopled than in England; and to give full effect to the natural resources of the country, a great part of the population should be swept from the soil.

Clearly, this sentence gives the impression that Malthus was advocating the extermination of the Irish. But the actual sentence that Malthus wrote reads, rather (Ricardo 2005)⁠ (emphasis added):

The land in Ireland is infinitely more peopled than in England; and to give full effect to the natural resources of the country, a great part of the population should be swept from the soil into large manufacturing and commercial Towns.

So, you see that Malthus wasn't proposing to kill anyone, rather, he was proposing the industrialization of Ireland in order to create prosperity in the country. Nevertheless, legends spread easily on the web and you can see the truncated sentence by Malthus repeated over and over to demonstrate that Malthus was an evil person who proposed the extermination of the poor. I can't think that Professor Mokyr truncated this phrase himself, but he was at least careless in cutting and pasting something that he read on the Web without worrying too much about verifying the original source.

The Web, indeed, is full of insults against Malthus. You can find an especially nasty (and misinformed one) attack against him at this link where you can read that, yes, the Irish famine was all a fault of Malthus who misinformed the British government, who then refused to help the poor Irish, who then starved - all based on that truncated sentence.

Sometimes, I have the feeling that we are swimming in propaganda, drinking propaganda, eating propaganda, and even being happy about doing that.

___________________________________________________________

Dabashi H, Mignolo W (2015) Can Non-Europeans Think? Zed Books

Mokyr J (1983) Why Ireland Starved. Routledge, London and New York

Ricardo D (2005) The Works and Correspondence of David Ricardo. Liberty Fund, Indianapolis

Sunday, October 2, 2016

This text was originally part of the book that I am writing, "The Seneca Effect", where it was meant to illustrate how new technologies can worsen problems, rather than solve them. Then, the book took an aspect and a structure where this piece wouldn't fit, so I removed it. But it can fit in the Cassandra Blog. Image above, Merlin advising King Arthur, from "mythencyclopedia"

Have you ever been dreaming of living in Roman times? Yes, those ancient and glorious times when the Romans had conquered all the known world and were ruling it by means of their legions, their laws, and their culture. But, if you were an ancient Roman, you would have known that you had a problem: the Roman Empire has often been under threat: rebellions, barbarians, all that. And, as a 21st-century person dreaming of those ancient times, you know that, eventually, the empire will fall. You know that Rome will be taken and sacked, that the Roman legion will be defeated and scattered, that the Roman ways will be lost and forgotten. It was the way history went but was it really unavoidable? Or could a wise emperor have done something to avoid that?

So, imagine that some powerful magic has you transferred to those remote times in the form of a Druid living in foggy Britannia, an ancestor of Merlin the wise, smart enough to figure out that something is rotten in the Roman Empire. Then, you know that it is a tradition of Druids to alert kings and rulers of the dangers ahead. After al, it is what Merlin did that for King Arthur. So, you want to do the same for the Roman Emperor. You want to use your 21st-century knowledge in order to save the empire.

Let's imagine that this druid lives during the golden age of the Empire, the time of the wise emperors. And let's imagine that the ruling wise emperor is actually Marcus Aurelius, the philosopher-emperor who left us his thoughts that we still read today. So, you, as that druid, leave your town of Eburacum (that today we call York) in foggy Britannia and you march all the way to Rome. Your fame has preceded you and, when you arrive in Rome, the Emperor receives you, happy to meet such a wise man from a remote province of the Empire. So, you are in front of the emperor. He looks wise, too, with his gray beard and his solemn “trabea” toga, all dyed in the sacred purple, as it befits to a reigning emperor. Maybe you would tell him something like this.

Emperor, greetings from remote Britannia! Greetings from a druid whom more than a few say is wise. Good Marcus, I walked all the way from Eburacum to Rome to advise you; hear my words! The Empire is in trouble, in great trouble. The gold mines of Iberia do not produce any more gold in such an abundance as they did long ago and the coffers of the state are becoming empty. And, without much gold and silver to pay the legionnaires, the legions are not any more so numerous as they used to be. And the people of the Empire suffer under weight of the taxation that's needed to keep manned the fortifications that protect the Empire from its enemies. Emperor, the legions are becoming smaller, the people poorer, and the fortification less safe. And the barbarians surrounding the empire are numerous and warlike and everyday they become more numerous and more warlike. Emperor, if you don't do something, one day the barbarians will overrun the fortifications, they will defeat and disperse the legions, and they will besiege and take Rome. And the great Roman Empire will be no more.

But, Emperor, I have wisdom that I can access by the powers I have as a druid, and it is wisdom that can help the empire! First of all, I can tell you that there are lands on the other side of the Great Ocean. It is a long travel to there, but if you send ships to those remote lands, you can find gold in abundance and replenish the coffers of the empire and with this gold you can pay the legionnaires and the Roman Army will be again as strong as it was in the old times. Then, Emperor, I can tell you that in the land I come from, there are black stones that burn. And these black stones are incredibly abundant. If you can send people to dig for them, with these black stones you can build great metal machines which, in turn, will build bigger and bigger machines. And these machines will do the work of many men and bring prosperity to the Empire. And, finally, emperor, I can tell you how to create a powder that burns; and it burns so fast that it makes a great noise and a great gust of wind comes out of it. And this powder can be made to catch fire inside a metal tube. And if one side of the tube is kept sealed and the other is open, you can place a lead ball into the tube, and the fire of the powder will project the ball fast and at a great distance and kill your enemies. And with this weapon your legions will easily defeat the barbarians. And this is the wisdom that i am bringing to you, Emperor. ”

The emperor looks at you, perplexed. He caresses his gray beard for a while. Then he speaks:

“Druid, I see that you know many things, and some of these things are truly wondrous to hear. And maybe, Druid, you are truly wise as some say you are. Yet, I daresay that this knowledge of yours may not be wisdom, after all. Let me tell you something about what you propose. First of all, it may be true that there are lands on the other side of the Great Ocean. And it may also be true that there is gold in these lands. But, Druid, there is gold also in much closer lands; and you should know that my predecessor, the good Emperor Trajan, may the Gods bless his memory, endeavored to invade the land that we call Dacia in order to obtain the gold that we knew was there. And you should know, druid, that the Roman legions fought hard and for a long time and covered themselves in glory and conquered that land and brought back much gold to Rome, But, druid, let me also tell you that the effort was great and the gold that could be brought to Rome was not so much that it could justify it. And so, if getting gold from a close land was so difficult and so expensive, how much more effort will take to get it from a much more remote one, on the other side of the Ocean, as you propose?

Then, druid, let me tell you something about the great machines that you propose to build and to power using those black stones that indeed I know exist in remote Britannia. Yes, maybe that would be possible. But the work of many men would be necessary to dig out the black stones. Would we have to weaken our fortifications or take men from farming to do that? And to bring the stones here, we would need a fleet of ships, but the fleet we have is engaged in bringing grain to Rome in order to feed the Romans. And, if we send the fleet to Britannia to load the black stones and carry them to Rome, what will the Romans eat? Would you want them to eat stones?

And, finally, druid, about those metal tubes that can kill people at a distance; yes, I understand that they could be a powerful weapon. But, druid, what would prevent our enemies, the barbarians, from getting those tubes themselves and using them against us? And if they were to build truly large ones, would they use them to bring down the great walls that defend the empire and the city of Rome?

The emperor keeps caressing his gray beard, looking at you. He remains silent for a while, then he speaks again, looking very solemn in his purple toga.

Druid, I understand that you may be sincere in telling me the things you told me and that you may really wishing to help the empire. Yet, I think that this pretended wisdom of yours is not useful to the empire and perhaps it is even dangerous for it. And, Druid, you should understand that I am the emperor of the Romans and I have power of life and death on everyone in the city of Rome and also on everyone within the limes of the Empire. And if I use my power it is to protect the empire from things that I judge dangerous for the empire. And so I was thinking that I could use this power to have your head lopped off, so that this knowledge of yours would not be a danger anymore for the Empire. But since I am steeped in the ways of philosophy and I know the sacredness of life, I will not do that. So, let me offer to you an escort that will lead you back to the town of Eburacum, in remote Britannia, where I trust you will stay and from where you will never come back here again.

Who

Ugo Bardi is a member of the Club of Rome and the author of "Extracted: how the quest for mineral resources is plundering the Planet" (Chelsea Green 2014). His most recent book is "The Seneca Effect" to be published by Springer in mid 2017

Listen! for no more the presage of my soul, Bride-like, shall peer from its secluding veil; But as the morning wind blows clear the east,More bright shall blow the wind of prophecy,And I will speak, but in dark speech no more.(Aeschylus, Agamemnon)

Ugo Bardi's blog

This blog is dedicated to exploring the future of humankind, affected by the decline of the availability of natural resources, the climate problem, and the human tendency of mismanaging both. The future doesn't look bright, but it is still possible to do something good if we don't discount the alerts of the modern Cassandras. (and don't forget that the ancient prophetess turned out to be always right).

Above: Cassandra by Evelyn De Morgan, 1898

Chimeras: another blog by UB

Dedicated to art, myths, literature, and history with a special attention to ancient monsters and deities.

The Seneca Effect

The Seneca Effect: is this what our future looks like?

Extracted

A report to the Club of Rome published by Chelsea Green. (click on image for a link)

Rules of the blog

I try to publish at least a post every week, typically on Mondays, but additional posts often appear on different days. Comments are moderated. You may reproduce my posts as you like, citing the source is appreciated!

About the author

Ugo Bardi teaches physical chemistry at the University of Florence, in Italy. He is interested in resource depletion, system dynamics modeling, climate science and renewable energy. Contact: ugo.bardi(whirlything)unifi.it